html,body{
    margin: 0;
    height: 100%;
}
.flex-full{
    flex: 1;
}
.flex-row{
    display: flex;
    flex-direction: row;
}
.flex-row-center{
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
}
.flex-col{
    display: flex;
    flex-direction: column;
}
.flex-col-center{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}